Information disclosure in Struktur Libheif
CVE-2026-47247
libheif is a HEIF and AVIF file format decoder and encoder. Prior to version 1.22.0, two bugs in libheif chain to leak process heap memory as visible pixel values in decoded grid images. An attacker who uploads a crafted AVIF/HEIC file to any server-side image processor (WordPress, Sharp/libvips, ImageMagick, etc.) can recover heap data - including library function pointers sufficient to defeat ASLR, or any other secret - from the publicly-downloadable transcoded JPEG/PNG/WebP output. Local attack vectors are also possible. Version 1.22.0 fixes the issue.
Vulnerability class: Information Disclosure
EPSS: 0.004 (37.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Struktur Libheif
- Strukturag Libheif — versions < 1.22.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-47247?
- CVE-2026-47247 is a high-severity vulnerability in Struktur Libheif, classified under Information Disclosure. CVSS score: 7.5/10. Published 2026-07-21.
- How severe is CVE-2026-47247?
- High severity. CVSS v3 base score is 7.5 out of 10.